Charlie at Manzano Laser Works thought it would be fun to build my old School Boat at 150% its original size. The up-sized model comes out to 27" long with an 8" beam. The model will build light, so a single 12V S-400 motor will be used for power.

So, as long as Charlie was cutting one for himself, I asked if he'd cut me one too as it looks like aone of those "quick and dirty" projects that will look great blasting around the pond on a lazy Saturday. So, let's get started.....

The hull consists of a balsa deck, four formers and the keel assembly. The wood sizes are basically the same as the original design, so balsa shims were placed on the frames where necessary to make the notches fit snugly. The assembly was glued together, then the chines were added using 2 laminations of 1/8 X 1/4 balsa rather then the original 3/32 X 3/16 wood, which fit the notches perfectly.

The bottom skins were added using 3/32 balsa rather then the original 1/16 sheet since the frame spacing is really pretty wide. The 3/32 sheet side skins will be glued in after the rudder and prop shaft tubes are glued in while access is still easy. They'll still be accessable on the finished model, but installing them will difinitely be easier with access through both sides.

Even though this was my hairbrain idea I am going to let you figure out the power.

I still have a sp400 motor but no speed control. Bunch of brushless stuff around the same size. I don't think I have anything over 1500kV. Think there is a prop that would fit one of those?

charlie

I have a couple of 12V S-400's here, so will try one of those on either a 3S Lipo or a 10 Cell NiCAD. I know it's going to need the weight, so the 10 cell might be the best bet -- besides, I still have 2 of them floating around here... Meanwhile, I also have a couple of old 20 or 30 amp airplane ESC's laying around too, so will probably go that way instead of shelling out the bucks for a new F/R car controller.

I still haven't figured out just how to guess at the size props are suitable for a brushless motor in boats, but guys in town are using 400 class outrunners w/ 1 1/4 - 1 1/2 inch 2 and 3 blades with pretty good success, though there's really no way to test for current draw without a data logger..

Charlie, No, not yet. Been too busy to get back on it, but can't wait to get going again. Everything I need to finish it is in hand, so it's down to sneeking it in when there's a few free minutes. Meanwhile, how's your's running . Can't wait to get them both out and run some formation....

The rudder and prop bearing tubes were fitted and glued in place, then the rudder servo. The rudder assembly was made up from brass tube and sheet and soldered together. The servo was glued to the bulkhead with silicon and when dry the linkage was set up using #2 pushrod and steel clevises.

The motor mount was built up ands installed, and when dry the motor was glued in place with silicone. There's plenty of easy access to the motor from the top, so the ESC won't be installed until after the boat is completed.

Images

The cabin was built stock, but because the original wood sizes were used, nothing fit right. To correct the spacing, a 1/16 X 1/8 balsa shim was glued on each end of the front and rear window frames. The cabin was then assembled as the original. I plan to work up a Flying Bridge just to add a little class to the finished model. Should look pretty cool when it's done.

Meanwhile, a finish sanding was done, then a coat of dope was brushed on. Will do a light sanding and apply a couple more coats of dope, then do the finish with silkspan to seal it all up.

Pat when you use the silkspan do you allow any of it to overlap at the bow?

Gravman, I lay up the silkspan in 5 sections; 2 on the bottom, 2 on the sides and a seperate piece on the transom. I'll overlap each section about 3/8" into its mating section so that all the corners are double thick. Makes it harder to sand through the sharp edges -- though care is still needed in those areas not to get too agressive and expose the wood. Then to toughen things up I'll likely as not add an aluminum cutwater and rear fenders.

Figured I'd get out this weekend and shot a coat of primer on the boat to prep for colors. Well, it turned out to be a beautiful day, and as it turned out, I was able to shoot all the colors. Remember, this is a "no cost, use what's here" project, so went with the colors I had in keeping with the theme.

Next I'll get the gold boot top on and as soon as winter passes into Indian Summer will get the clear coat shot. Then it'll be time to button up the inside and finish her up.

PAT

Images

Figured I'd get out this weekend and shot a coat of primer on the boat to prep for colors. Well, it turned out to be a beautiful day, and as it turned out, I was able to shoot all the colors. Remember, this is a "no cost, use what's here" project, so went with the colors I had in keeping with the theme.

Next I'll get the gold boot top on and as soon as winter passes into Indian Summer will get the clear coat shot. Then it'll be time to button up the inside and finish her up.

PAT

Looks like a great winter project for my 9-year-old son. Will Charlie carry a kit for this version? (I like the size.)

While I would be happy to cut parts for people the larger version should be considered more a scratch build than a kit build. The differences in parts thicknesses means there is a lot of shims that need to be used during the build. Not hard, but, not like a Midwest kit for example.

And, if you are like me and want to overpower it, will need a fiberglass job.

Aero,

There are no instructions for either of these. You could print out the plans for the original and use Pat's original thread as instructions.

Well, after months of neglect I figured it was high time to get the Biggered-Up SB project back out and finish it up. Really, all that was left was to install the prop shaft and get the last of the work done on the cabin, so finishing the model took less then a day.

I used a 1/2A plastic prop from Dumas on the 6V S-400 motor and will power it up with a 5400 mah 2S Li-Poly battery. And since the model finished out extremely light, it required 40 oz. of ballast to pull a water line.

I had planned to do the maiden run this morning, but got weathered out, so will have to try again later. Will post up the results once it's done.